Transaortic mitral valve secondary chordal cutting in patients with obstructive hypertrophic cardiomyopathy and mild septal hypertrophy.

A proportion of patients with obstructive hypertrophic cardiomyopathy (HCM) and severe heart failure symptoms have only mild septal hypertrophy (1). In such patients, mitral valve (MV) abnormalities play an important role in systolic MV leaflets displacement into the left ventricular LV outflow tract and blood flow obstruction (1-3). Therefore, conventional septal myectomy alone may not be sufficient to relieve LV obstruction and symptoms, and often MV repair or replacement is the surgical alternative (1). Transaortic cutting of MV secondary chordae is a novel technique for MV repair that, associated with a shallow septal myectomy, abolishes the outflow gradient, relieves heart failure symptoms, and avoids MV replacement in patients with obstructive HCM and mild septal thickness (4). A 45-year-old female patient with obstructive HCM, mild septal hypertrophy and severe heart failure symptoms (New York Heart Association functional class III) unresponsive to medications was referred to our institution for surgical treatment of LV outflow obstruction. Physical examination revealed blood pressure 124/72 mmHg and heart rate of 72 BPM on bisoprolol 10 mg/day. Transthoracic echocardiography showed mild septal hypertrophy (17 mm) confined mainly to the basal and medium portion of the anterior septum, with marked systolic anterior motion of the MV leaflets and leaflet-septal contact at rest, and moderate left atrial dilatation. Doppler echocardiography showed an LV outflow maximal gradient of 72 mmHg under basal conditions, moderate-to-severe MV regurgitation, and a systolic pulmonary pressure of 32 mmHg. Cardiac magnetic resonance documented a small area of intramural delayed enhancement on the anterior septum. Coronary angiography was normal. Because of severe outflow gradient and heart failure symptoms, relatively mild septal thickness, MV leaflets with anterior leaflet tenting, and important MV regurgitation, we planned a shallow surgical myectomy, possibly associated with MV secondary chordal cutting through a median sternotomy.